xref: /freebsd/sys/arm/ti/ti_adc.c (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)
1 /*-
2  * Copyright 2014 Luiz Otavio O Souza <loos@freebsd.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_evdev.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 
36 #include <sys/conf.h>
37 #include <sys/kernel.h>
38 #include <sys/limits.h>
39 #include <sys/lock.h>
40 #include <sys/module.h>
41 #include <sys/mutex.h>
42 #include <sys/condvar.h>
43 #include <sys/resource.h>
44 #include <sys/rman.h>
45 #include <sys/sysctl.h>
46 #include <sys/selinfo.h>
47 #include <sys/poll.h>
48 #include <sys/uio.h>
49 
50 #include <machine/bus.h>
51 
52 #include <dev/ofw/openfirm.h>
53 #include <dev/ofw/ofw_bus.h>
54 #include <dev/ofw/ofw_bus_subr.h>
55 
56 #ifdef EVDEV_SUPPORT
57 #include <dev/evdev/input.h>
58 #include <dev/evdev/evdev.h>
59 #endif
60 
61 #include <arm/ti/ti_prcm.h>
62 #include <arm/ti/ti_adcreg.h>
63 #include <arm/ti/ti_adcvar.h>
64 
65 #undef	DEBUG_TSC
66 
67 #define	DEFAULT_CHARGE_DELAY	0x400
68 #define	STEPDLY_OPEN		0x98
69 
70 #define	ORDER_XP	0
71 #define	ORDER_XN	1
72 #define	ORDER_YP	2
73 #define	ORDER_YN	3
74 
75 /* Define our 8 steps, one for each input channel. */
76 static struct ti_adc_input ti_adc_inputs[TI_ADC_NPINS] = {
77 	{ .stepconfig = ADC_STEPCFG(1), .stepdelay = ADC_STEPDLY(1) },
78 	{ .stepconfig = ADC_STEPCFG(2), .stepdelay = ADC_STEPDLY(2) },
79 	{ .stepconfig = ADC_STEPCFG(3), .stepdelay = ADC_STEPDLY(3) },
80 	{ .stepconfig = ADC_STEPCFG(4), .stepdelay = ADC_STEPDLY(4) },
81 	{ .stepconfig = ADC_STEPCFG(5), .stepdelay = ADC_STEPDLY(5) },
82 	{ .stepconfig = ADC_STEPCFG(6), .stepdelay = ADC_STEPDLY(6) },
83 	{ .stepconfig = ADC_STEPCFG(7), .stepdelay = ADC_STEPDLY(7) },
84 	{ .stepconfig = ADC_STEPCFG(8), .stepdelay = ADC_STEPDLY(8) },
85 };
86 
87 static int ti_adc_samples[5] = { 0, 2, 4, 8, 16 };
88 
89 static int ti_adc_detach(device_t dev);
90 
91 #ifdef EVDEV_SUPPORT
92 static void
93 ti_adc_ev_report(struct ti_adc_softc *sc)
94 {
95 
96 	evdev_push_event(sc->sc_evdev, EV_ABS, ABS_X, sc->sc_x);
97 	evdev_push_event(sc->sc_evdev, EV_ABS, ABS_Y, sc->sc_y);
98 	evdev_push_event(sc->sc_evdev, EV_KEY, BTN_TOUCH, sc->sc_pen_down);
99 	evdev_sync(sc->sc_evdev);
100 }
101 #endif /* EVDEV */
102 
103 static void
104 ti_adc_enable(struct ti_adc_softc *sc)
105 {
106 	uint32_t reg;
107 
108 	TI_ADC_LOCK_ASSERT(sc);
109 
110 	if (sc->sc_last_state == 1)
111 		return;
112 
113 	/* Enable the FIFO0 threshold and the end of sequence interrupt. */
114 	ADC_WRITE4(sc, ADC_IRQENABLE_SET,
115 	    ADC_IRQ_FIFO0_THRES | ADC_IRQ_FIFO1_THRES | ADC_IRQ_END_OF_SEQ);
116 
117 	reg = ADC_CTRL_STEP_WP | ADC_CTRL_STEP_ID;
118 	if (sc->sc_tsc_wires > 0) {
119 		reg |= ADC_CTRL_TSC_ENABLE;
120 		switch (sc->sc_tsc_wires) {
121 		case 4:
122 			reg |= ADC_CTRL_TSC_4WIRE;
123 			break;
124 		case 5:
125 			reg |= ADC_CTRL_TSC_5WIRE;
126 			break;
127 		case 8:
128 			reg |= ADC_CTRL_TSC_8WIRE;
129 			break;
130 		default:
131 			break;
132 		}
133 	}
134 	reg |= ADC_CTRL_ENABLE;
135 	/* Enable the ADC.  Run thru enabled steps, start the conversions. */
136 	ADC_WRITE4(sc, ADC_CTRL, reg);
137 
138 	sc->sc_last_state = 1;
139 }
140 
141 static void
142 ti_adc_disable(struct ti_adc_softc *sc)
143 {
144 	int count;
145 	uint32_t data;
146 
147 	TI_ADC_LOCK_ASSERT(sc);
148 
149 	if (sc->sc_last_state == 0)
150 		return;
151 
152 	/* Disable all the enabled steps. */
153 	ADC_WRITE4(sc, ADC_STEPENABLE, 0);
154 
155 	/* Disable the ADC. */
156 	ADC_WRITE4(sc, ADC_CTRL, ADC_READ4(sc, ADC_CTRL) & ~ADC_CTRL_ENABLE);
157 
158 	/* Disable the FIFO0 threshold and the end of sequence interrupt. */
159 	ADC_WRITE4(sc, ADC_IRQENABLE_CLR,
160 	    ADC_IRQ_FIFO0_THRES | ADC_IRQ_FIFO1_THRES | ADC_IRQ_END_OF_SEQ);
161 
162 	/* ACK any pending interrupt. */
163 	ADC_WRITE4(sc, ADC_IRQSTATUS, ADC_READ4(sc, ADC_IRQSTATUS));
164 
165 	/* Drain the FIFO data. */
166 	count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
167 	while (count > 0) {
168 		data = ADC_READ4(sc, ADC_FIFO0DATA);
169 		count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
170 	}
171 
172 	count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
173 	while (count > 0) {
174 		data = ADC_READ4(sc, ADC_FIFO1DATA);
175 		count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
176 	}
177 
178 	sc->sc_last_state = 0;
179 }
180 
181 static int
182 ti_adc_setup(struct ti_adc_softc *sc)
183 {
184 	int ain, i;
185 	uint32_t enabled;
186 
187 	TI_ADC_LOCK_ASSERT(sc);
188 
189 	/* Check for enabled inputs. */
190 	enabled = sc->sc_tsc_enabled;
191 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
192 		ain = sc->sc_adc_channels[i];
193 		if (ti_adc_inputs[ain].enable)
194 			enabled |= (1U << (ain + 1));
195 	}
196 
197 	/* Set the ADC global status. */
198 	if (enabled != 0) {
199 		ti_adc_enable(sc);
200 		/* Update the enabled steps. */
201 		if (enabled != ADC_READ4(sc, ADC_STEPENABLE))
202 			ADC_WRITE4(sc, ADC_STEPENABLE, enabled);
203 	} else
204 		ti_adc_disable(sc);
205 
206 	return (0);
207 }
208 
209 static void
210 ti_adc_input_setup(struct ti_adc_softc *sc, int32_t ain)
211 {
212 	struct ti_adc_input *input;
213 	uint32_t reg, val;
214 
215 	TI_ADC_LOCK_ASSERT(sc);
216 
217 	input = &ti_adc_inputs[ain];
218 	reg = input->stepconfig;
219 	val = ADC_READ4(sc, reg);
220 
221 	/* Set single ended operation. */
222 	val &= ~ADC_STEP_DIFF_CNTRL;
223 
224 	/* Set the negative voltage reference. */
225 	val &= ~ADC_STEP_RFM_MSK;
226 
227 	/* Set the positive voltage reference. */
228 	val &= ~ADC_STEP_RFP_MSK;
229 
230 	/* Set the samples average. */
231 	val &= ~ADC_STEP_AVG_MSK;
232 	val |= input->samples << ADC_STEP_AVG_SHIFT;
233 
234 	/* Select the desired input. */
235 	val &= ~ADC_STEP_INP_MSK;
236 	val |= ain << ADC_STEP_INP_SHIFT;
237 
238 	/* Set the ADC to one-shot mode. */
239 	val &= ~ADC_STEP_MODE_MSK;
240 
241 	ADC_WRITE4(sc, reg, val);
242 }
243 
244 static void
245 ti_adc_reset(struct ti_adc_softc *sc)
246 {
247 	int ain, i;
248 
249 	TI_ADC_LOCK_ASSERT(sc);
250 
251 	/* Disable all the inputs. */
252 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
253 		ain = sc->sc_adc_channels[i];
254 		ti_adc_inputs[ain].enable = 0;
255 	}
256 }
257 
258 static int
259 ti_adc_clockdiv_proc(SYSCTL_HANDLER_ARGS)
260 {
261 	int error, reg;
262 	struct ti_adc_softc *sc;
263 
264 	sc = (struct ti_adc_softc *)arg1;
265 
266 	TI_ADC_LOCK(sc);
267 	reg = (int)ADC_READ4(sc, ADC_CLKDIV) + 1;
268 	TI_ADC_UNLOCK(sc);
269 
270 	error = sysctl_handle_int(oidp, &reg, sizeof(reg), req);
271 	if (error != 0 || req->newptr == NULL)
272 		return (error);
273 
274 	/*
275 	 * The actual written value is the prescaler setting - 1.
276 	 * Enforce a minimum value of 10 (i.e. 9) which limits the maximum
277 	 * ADC clock to ~2.4Mhz (CLK_M_OSC / 10).
278 	 */
279 	reg--;
280 	if (reg < 9)
281 		reg = 9;
282 	if (reg > USHRT_MAX)
283 		reg = USHRT_MAX;
284 
285 	TI_ADC_LOCK(sc);
286 	/* Disable the ADC. */
287 	ti_adc_disable(sc);
288 	/* Update the ADC prescaler setting. */
289 	ADC_WRITE4(sc, ADC_CLKDIV, reg);
290 	/* Enable the ADC again. */
291 	ti_adc_setup(sc);
292 	TI_ADC_UNLOCK(sc);
293 
294 	return (0);
295 }
296 
297 static int
298 ti_adc_enable_proc(SYSCTL_HANDLER_ARGS)
299 {
300 	int error;
301 	int32_t enable;
302 	struct ti_adc_softc *sc;
303 	struct ti_adc_input *input;
304 
305 	input = (struct ti_adc_input *)arg1;
306 	sc = input->sc;
307 
308 	enable = input->enable;
309 	error = sysctl_handle_int(oidp, &enable, sizeof(enable),
310 	    req);
311 	if (error != 0 || req->newptr == NULL)
312 		return (error);
313 
314 	if (enable)
315 		enable = 1;
316 
317 	TI_ADC_LOCK(sc);
318 	/* Setup the ADC as needed. */
319 	if (input->enable != enable) {
320 		input->enable = enable;
321 		ti_adc_setup(sc);
322 		if (input->enable == 0)
323 			input->value = 0;
324 	}
325 	TI_ADC_UNLOCK(sc);
326 
327 	return (0);
328 }
329 
330 static int
331 ti_adc_open_delay_proc(SYSCTL_HANDLER_ARGS)
332 {
333 	int error, reg;
334 	struct ti_adc_softc *sc;
335 	struct ti_adc_input *input;
336 
337 	input = (struct ti_adc_input *)arg1;
338 	sc = input->sc;
339 
340 	TI_ADC_LOCK(sc);
341 	reg = (int)ADC_READ4(sc, input->stepdelay) & ADC_STEP_OPEN_DELAY;
342 	TI_ADC_UNLOCK(sc);
343 
344 	error = sysctl_handle_int(oidp, &reg, sizeof(reg), req);
345 	if (error != 0 || req->newptr == NULL)
346 		return (error);
347 
348 	if (reg < 0)
349 		reg = 0;
350 
351 	TI_ADC_LOCK(sc);
352 	ADC_WRITE4(sc, input->stepdelay, reg & ADC_STEP_OPEN_DELAY);
353 	TI_ADC_UNLOCK(sc);
354 
355 	return (0);
356 }
357 
358 static int
359 ti_adc_samples_avg_proc(SYSCTL_HANDLER_ARGS)
360 {
361 	int error, samples, i;
362 	struct ti_adc_softc *sc;
363 	struct ti_adc_input *input;
364 
365 	input = (struct ti_adc_input *)arg1;
366 	sc = input->sc;
367 
368 	if (input->samples > nitems(ti_adc_samples))
369 		input->samples = nitems(ti_adc_samples);
370 	samples = ti_adc_samples[input->samples];
371 
372 	error = sysctl_handle_int(oidp, &samples, 0, req);
373 	if (error != 0 || req->newptr == NULL)
374 		return (error);
375 
376 	TI_ADC_LOCK(sc);
377 	if (samples != ti_adc_samples[input->samples]) {
378 		input->samples = 0;
379 		for (i = 0; i < nitems(ti_adc_samples); i++)
380 			if (samples >= ti_adc_samples[i])
381 				input->samples = i;
382 		ti_adc_input_setup(sc, input->input);
383 	}
384 	TI_ADC_UNLOCK(sc);
385 
386 	return (error);
387 }
388 
389 static void
390 ti_adc_read_data(struct ti_adc_softc *sc)
391 {
392 	int count, ain;
393 	struct ti_adc_input *input;
394 	uint32_t data;
395 
396 	TI_ADC_LOCK_ASSERT(sc);
397 
398 	/* Read the available data. */
399 	count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
400 	while (count > 0) {
401 		data = ADC_READ4(sc, ADC_FIFO0DATA);
402 		ain = (data & ADC_FIFO_STEP_ID_MSK) >> ADC_FIFO_STEP_ID_SHIFT;
403 		input = &ti_adc_inputs[ain];
404 		if (input->enable == 0)
405 			input->value = 0;
406 		else
407 			input->value = (int32_t)(data & ADC_FIFO_DATA_MSK);
408 		count = ADC_READ4(sc, ADC_FIFO0COUNT) & ADC_FIFO_COUNT_MSK;
409 	}
410 }
411 
412 static int
413 cmp_values(const void *a, const void *b)
414 {
415 	const uint32_t *v1, *v2;
416 	v1 = a;
417 	v2 = b;
418 	if (*v1 < *v2)
419 		return -1;
420 	if (*v1 > *v2)
421 		return 1;
422 
423 	return (0);
424 }
425 
426 static void
427 ti_adc_tsc_read_data(struct ti_adc_softc *sc)
428 {
429 	int count;
430 	uint32_t data[16];
431 	uint32_t x, y;
432 	int i, start, end;
433 
434 	TI_ADC_LOCK_ASSERT(sc);
435 
436 	/* Read the available data. */
437 	count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
438 	if (count == 0)
439 		return;
440 
441 	i = 0;
442 	while (count > 0) {
443 		data[i++] = ADC_READ4(sc, ADC_FIFO1DATA) & ADC_FIFO_DATA_MSK;
444 		count = ADC_READ4(sc, ADC_FIFO1COUNT) & ADC_FIFO_COUNT_MSK;
445 	}
446 
447 	if (sc->sc_coord_readouts > 3) {
448 		start = 1;
449 		end = sc->sc_coord_readouts - 1;
450 		qsort(data, sc->sc_coord_readouts,
451 			sizeof(data[0]), &cmp_values);
452 		qsort(&data[sc->sc_coord_readouts + 2],
453 			sc->sc_coord_readouts,
454 			sizeof(data[0]), &cmp_values);
455 	}
456 	else {
457 		start = 0;
458 		end = sc->sc_coord_readouts;
459 	}
460 
461 	x = y = 0;
462 	for (i = start; i < end; i++)
463 		y += data[i];
464 	y /= (end - start);
465 
466 	for (i = sc->sc_coord_readouts + 2 + start; i < sc->sc_coord_readouts + 2 + end; i++)
467 		x += data[i];
468 	x /= (end - start);
469 
470 #ifdef DEBUG_TSC
471 	device_printf(sc->sc_dev, "touchscreen x: %d, y: %d\n", x, y);
472 #endif
473 
474 #ifdef EVDEV_SUPPORT
475 	if ((sc->sc_x != x) || (sc->sc_y != y)) {
476 		sc->sc_x = x;
477 		sc->sc_y = y;
478 		ti_adc_ev_report(sc);
479 	}
480 #endif
481 }
482 
483 static void
484 ti_adc_intr_locked(struct ti_adc_softc *sc, uint32_t status)
485 {
486 	/* Read the available data. */
487 	if (status & ADC_IRQ_FIFO0_THRES)
488 		ti_adc_read_data(sc);
489 }
490 
491 static void
492 ti_adc_tsc_intr_locked(struct ti_adc_softc *sc, uint32_t status)
493 {
494 	/* Read the available data. */
495 	if (status & ADC_IRQ_FIFO1_THRES)
496 		ti_adc_tsc_read_data(sc);
497 
498 }
499 
500 static void
501 ti_adc_intr(void *arg)
502 {
503 	struct ti_adc_softc *sc;
504 	uint32_t status, rawstatus;
505 
506 	sc = (struct ti_adc_softc *)arg;
507 
508 	TI_ADC_LOCK(sc);
509 
510 	rawstatus = ADC_READ4(sc, ADC_IRQSTATUS_RAW);
511 	status = ADC_READ4(sc, ADC_IRQSTATUS);
512 
513 	if (rawstatus & ADC_IRQ_HW_PEN_ASYNC) {
514 		sc->sc_pen_down = 1;
515 		status |= ADC_IRQ_HW_PEN_ASYNC;
516 		ADC_WRITE4(sc, ADC_IRQENABLE_CLR,
517 			ADC_IRQ_HW_PEN_ASYNC);
518 #ifdef EVDEV_SUPPORT
519 		ti_adc_ev_report(sc);
520 #endif
521 	}
522 
523 	if (rawstatus & ADC_IRQ_PEN_UP) {
524 		sc->sc_pen_down = 0;
525 		status |= ADC_IRQ_PEN_UP;
526 #ifdef EVDEV_SUPPORT
527 		ti_adc_ev_report(sc);
528 #endif
529 	}
530 
531 	if (status & ADC_IRQ_FIFO0_THRES)
532 		ti_adc_intr_locked(sc, status);
533 
534 	if (status & ADC_IRQ_FIFO1_THRES)
535 		ti_adc_tsc_intr_locked(sc, status);
536 
537 	if (status) {
538 		/* ACK the interrupt. */
539 		ADC_WRITE4(sc, ADC_IRQSTATUS, status);
540 	}
541 
542 	/* Start the next conversion ? */
543 	if (status & ADC_IRQ_END_OF_SEQ)
544 		ti_adc_setup(sc);
545 
546 	TI_ADC_UNLOCK(sc);
547 }
548 
549 static void
550 ti_adc_sysctl_init(struct ti_adc_softc *sc)
551 {
552 	char pinbuf[3];
553 	struct sysctl_ctx_list *ctx;
554 	struct sysctl_oid *tree_node, *inp_node, *inpN_node;
555 	struct sysctl_oid_list *tree, *inp_tree, *inpN_tree;
556 	int ain, i;
557 
558 	/*
559 	 * Add per-pin sysctl tree/handlers.
560 	 */
561 	ctx = device_get_sysctl_ctx(sc->sc_dev);
562 	tree_node = device_get_sysctl_tree(sc->sc_dev);
563 	tree = SYSCTL_CHILDREN(tree_node);
564 	SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "clockdiv",
565 	    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,  sc, 0,
566 	    ti_adc_clockdiv_proc, "IU", "ADC clock prescaler");
567 	inp_node = SYSCTL_ADD_NODE(ctx, tree, OID_AUTO, "ain",
568 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "ADC inputs");
569 	inp_tree = SYSCTL_CHILDREN(inp_node);
570 
571 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
572 		ain = sc->sc_adc_channels[i];
573 
574 		snprintf(pinbuf, sizeof(pinbuf), "%d", ain);
575 		inpN_node = SYSCTL_ADD_NODE(ctx, inp_tree, OID_AUTO, pinbuf,
576 		    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "ADC input");
577 		inpN_tree = SYSCTL_CHILDREN(inpN_node);
578 
579 		SYSCTL_ADD_PROC(ctx, inpN_tree, OID_AUTO, "enable",
580 		    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,
581 		    &ti_adc_inputs[ain], 0,
582 		    ti_adc_enable_proc, "IU", "Enable ADC input");
583 		SYSCTL_ADD_PROC(ctx, inpN_tree, OID_AUTO, "open_delay",
584 		    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,
585 		    &ti_adc_inputs[ain], 0,
586 		    ti_adc_open_delay_proc, "IU", "ADC open delay");
587 		SYSCTL_ADD_PROC(ctx, inpN_tree, OID_AUTO, "samples_avg",
588 		    CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_NEEDGIANT,
589 		    &ti_adc_inputs[ain], 0,
590 		    ti_adc_samples_avg_proc, "IU", "ADC samples average");
591 		SYSCTL_ADD_INT(ctx, inpN_tree, OID_AUTO, "input",
592 		    CTLFLAG_RD, &ti_adc_inputs[ain].value, 0,
593 		    "Converted raw value for the ADC input");
594 	}
595 }
596 
597 static void
598 ti_adc_inputs_init(struct ti_adc_softc *sc)
599 {
600 	int ain, i;
601 	struct ti_adc_input *input;
602 
603 	TI_ADC_LOCK(sc);
604 	for (i = 0; i < sc->sc_adc_nchannels; i++) {
605 		ain = sc->sc_adc_channels[i];
606 		input = &ti_adc_inputs[ain];
607 		input->sc = sc;
608 		input->input = ain;
609 		input->value = 0;
610 		input->enable = 0;
611 		input->samples = 0;
612 		ti_adc_input_setup(sc, ain);
613 	}
614 	TI_ADC_UNLOCK(sc);
615 }
616 
617 static void
618 ti_adc_tsc_init(struct ti_adc_softc *sc)
619 {
620 	int i, start_step, end_step;
621 	uint32_t stepconfig, val;
622 
623 	TI_ADC_LOCK(sc);
624 
625 	/* X coordinates */
626 	stepconfig = ADC_STEP_FIFO1 | (4 << ADC_STEP_AVG_SHIFT) |
627 	    ADC_STEP_MODE_HW_ONESHOT | sc->sc_xp_bit;
628 	if (sc->sc_tsc_wires == 4)
629 		stepconfig |= ADC_STEP_INP(sc->sc_yp_inp) | sc->sc_xn_bit;
630 	else if (sc->sc_tsc_wires == 5)
631 		stepconfig |= ADC_STEP_INP(4) |
632 			sc->sc_xn_bit | sc->sc_yn_bit | sc->sc_yp_bit;
633 	else if (sc->sc_tsc_wires == 8)
634 		stepconfig |= ADC_STEP_INP(sc->sc_yp_inp) | sc->sc_xn_bit;
635 
636 	start_step = ADC_STEPS - sc->sc_coord_readouts + 1;
637 	end_step = start_step + sc->sc_coord_readouts - 1;
638 	for (i = start_step; i <= end_step; i++) {
639 		ADC_WRITE4(sc, ADC_STEPCFG(i), stepconfig);
640 		ADC_WRITE4(sc, ADC_STEPDLY(i), STEPDLY_OPEN);
641 	}
642 
643 	/* Y coordinates */
644 	stepconfig = ADC_STEP_FIFO1 | (4 << ADC_STEP_AVG_SHIFT) |
645 	    ADC_STEP_MODE_HW_ONESHOT | sc->sc_yn_bit |
646 	    ADC_STEP_INM(8);
647 	if (sc->sc_tsc_wires == 4)
648 		stepconfig |= ADC_STEP_INP(sc->sc_xp_inp) | sc->sc_yp_bit;
649 	else if (sc->sc_tsc_wires == 5)
650 		stepconfig |= ADC_STEP_INP(4) |
651 			sc->sc_xp_bit | sc->sc_xn_bit | sc->sc_yp_bit;
652 	else if (sc->sc_tsc_wires == 8)
653 		stepconfig |= ADC_STEP_INP(sc->sc_xp_inp) | sc->sc_yp_bit;
654 
655 	start_step = ADC_STEPS - (sc->sc_coord_readouts*2 + 2) + 1;
656 	end_step = start_step + sc->sc_coord_readouts - 1;
657 	for (i = start_step; i <= end_step; i++) {
658 		ADC_WRITE4(sc, ADC_STEPCFG(i), stepconfig);
659 		ADC_WRITE4(sc, ADC_STEPDLY(i), STEPDLY_OPEN);
660 	}
661 
662 	/* Charge config */
663 	val = ADC_READ4(sc, ADC_IDLECONFIG);
664 	ADC_WRITE4(sc, ADC_TC_CHARGE_STEPCONFIG, val);
665 	ADC_WRITE4(sc, ADC_TC_CHARGE_DELAY, sc->sc_charge_delay);
666 
667 	/* 2 steps for Z */
668 	start_step = ADC_STEPS - (sc->sc_coord_readouts + 2) + 1;
669 	stepconfig = ADC_STEP_FIFO1 | (4 << ADC_STEP_AVG_SHIFT) |
670 	    ADC_STEP_MODE_HW_ONESHOT | sc->sc_yp_bit |
671 	    sc->sc_xn_bit | ADC_STEP_INP(sc->sc_xp_inp) |
672 	    ADC_STEP_INM(8);
673 	ADC_WRITE4(sc, ADC_STEPCFG(start_step), stepconfig);
674 	ADC_WRITE4(sc, ADC_STEPDLY(start_step), STEPDLY_OPEN);
675 	start_step++;
676 	stepconfig |= ADC_STEP_INP(sc->sc_yn_inp);
677 	ADC_WRITE4(sc, ADC_STEPCFG(start_step), stepconfig);
678 	ADC_WRITE4(sc, ADC_STEPDLY(start_step), STEPDLY_OPEN);
679 
680 	ADC_WRITE4(sc, ADC_FIFO1THRESHOLD, (sc->sc_coord_readouts*2 + 2) - 1);
681 
682 	sc->sc_tsc_enabled = 1;
683 	start_step = ADC_STEPS - (sc->sc_coord_readouts*2 + 2) + 1;
684 	end_step = ADC_STEPS;
685 	for (i = start_step; i <= end_step; i++) {
686 		sc->sc_tsc_enabled |= (1 << i);
687 	}
688 
689 
690 	TI_ADC_UNLOCK(sc);
691 }
692 
693 static void
694 ti_adc_idlestep_init(struct ti_adc_softc *sc)
695 {
696 	uint32_t val;
697 
698 	val = ADC_STEP_YNN_SW | ADC_STEP_INM(8) | ADC_STEP_INP(8) | ADC_STEP_YPN_SW;
699 
700 	ADC_WRITE4(sc, ADC_IDLECONFIG, val);
701 }
702 
703 static int
704 ti_adc_config_wires(struct ti_adc_softc *sc, int *wire_configs, int nwire_configs)
705 {
706 	int i;
707 	int wire, ai;
708 
709 	for (i = 0; i < nwire_configs; i++) {
710 		wire = wire_configs[i] & 0xf;
711 		ai = (wire_configs[i] >> 4) & 0xf;
712 		switch (wire) {
713 		case ORDER_XP:
714 			sc->sc_xp_bit = ADC_STEP_XPP_SW;
715 			sc->sc_xp_inp = ai;
716 			break;
717 		case ORDER_XN:
718 			sc->sc_xn_bit = ADC_STEP_XNN_SW;
719 			sc->sc_xn_inp = ai;
720 			break;
721 		case ORDER_YP:
722 			sc->sc_yp_bit = ADC_STEP_YPP_SW;
723 			sc->sc_yp_inp = ai;
724 			break;
725 		case ORDER_YN:
726 			sc->sc_yn_bit = ADC_STEP_YNN_SW;
727 			sc->sc_yn_inp = ai;
728 			break;
729 		default:
730 			device_printf(sc->sc_dev, "Invalid wire config\n");
731 			return (-1);
732 		}
733 	}
734 	return (0);
735 }
736 
737 static int
738 ti_adc_probe(device_t dev)
739 {
740 
741 	if (!ofw_bus_is_compatible(dev, "ti,am3359-tscadc"))
742 		return (ENXIO);
743 	device_set_desc(dev, "TI ADC controller");
744 
745 	return (BUS_PROBE_DEFAULT);
746 }
747 
748 static int
749 ti_adc_attach(device_t dev)
750 {
751 	int err, rid, i;
752 	struct ti_adc_softc *sc;
753 	uint32_t rev, reg;
754 	phandle_t node, child;
755 	pcell_t cell;
756 	int *channels;
757 	int nwire_configs;
758 	int *wire_configs;
759 
760 	sc = device_get_softc(dev);
761 	sc->sc_dev = dev;
762 
763 	node = ofw_bus_get_node(dev);
764 
765 	sc->sc_tsc_wires = 0;
766 	sc->sc_coord_readouts = 1;
767 	sc->sc_x_plate_resistance = 0;
768 	sc->sc_charge_delay = DEFAULT_CHARGE_DELAY;
769 	/* Read "tsc" node properties */
770 	child = ofw_bus_find_child(node, "tsc");
771 	if (child != 0 && OF_hasprop(child, "ti,wires")) {
772 		if ((OF_getencprop(child, "ti,wires", &cell, sizeof(cell))) > 0)
773 			sc->sc_tsc_wires = cell;
774 		if ((OF_getencprop(child, "ti,coordinate-readouts", &cell,
775 		    sizeof(cell))) > 0)
776 			sc->sc_coord_readouts = cell;
777 		if ((OF_getencprop(child, "ti,x-plate-resistance", &cell,
778 		    sizeof(cell))) > 0)
779 			sc->sc_x_plate_resistance = cell;
780 		if ((OF_getencprop(child, "ti,charge-delay", &cell,
781 		    sizeof(cell))) > 0)
782 			sc->sc_charge_delay = cell;
783 		nwire_configs = OF_getencprop_alloc_multi(child,
784 		    "ti,wire-config", sizeof(*wire_configs),
785 		    (void **)&wire_configs);
786 		if (nwire_configs != sc->sc_tsc_wires) {
787 			device_printf(sc->sc_dev,
788 			    "invalid number of ti,wire-config: %d (should be %d)\n",
789 			    nwire_configs, sc->sc_tsc_wires);
790 			OF_prop_free(wire_configs);
791 			return (EINVAL);
792 		}
793 		err = ti_adc_config_wires(sc, wire_configs, nwire_configs);
794 		OF_prop_free(wire_configs);
795 		if (err)
796 			return (EINVAL);
797 	}
798 
799 	/* Read "adc" node properties */
800 	child = ofw_bus_find_child(node, "adc");
801 	if (child != 0) {
802 		sc->sc_adc_nchannels = OF_getencprop_alloc_multi(child,
803 		    "ti,adc-channels", sizeof(*channels), (void **)&channels);
804 		if (sc->sc_adc_nchannels > 0) {
805 			for (i = 0; i < sc->sc_adc_nchannels; i++)
806 				sc->sc_adc_channels[i] = channels[i];
807 			OF_prop_free(channels);
808 		}
809 	}
810 
811 	/* Sanity check FDT data */
812 	if (sc->sc_tsc_wires + sc->sc_adc_nchannels > TI_ADC_NPINS) {
813 		device_printf(dev, "total number of chanels (%d) is larger than %d\n",
814 		    sc->sc_tsc_wires + sc->sc_adc_nchannels, TI_ADC_NPINS);
815 		return (ENXIO);
816 	}
817 
818 	rid = 0;
819 	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
820 	    RF_ACTIVE);
821 	if (!sc->sc_mem_res) {
822 		device_printf(dev, "cannot allocate memory window\n");
823 		return (ENXIO);
824 	}
825 
826 	/* Activate the ADC_TSC module. */
827 	err = ti_prcm_clk_enable(TSC_ADC_CLK);
828 	if (err)
829 		return (err);
830 
831 	rid = 0;
832 	sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
833 	    RF_ACTIVE);
834 	if (!sc->sc_irq_res) {
835 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
836 		device_printf(dev, "cannot allocate interrupt\n");
837 		return (ENXIO);
838 	}
839 
840 	if (bus_setup_intr(dev, sc->sc_irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
841 	    NULL, ti_adc_intr, sc, &sc->sc_intrhand) != 0) {
842 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
843 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
844 		device_printf(dev, "Unable to setup the irq handler.\n");
845 		return (ENXIO);
846 	}
847 
848 	/* Check the ADC revision. */
849 	rev = ADC_READ4(sc, ADC_REVISION);
850 	device_printf(dev,
851 	    "scheme: %#x func: %#x rtl: %d rev: %d.%d custom rev: %d\n",
852 	    (rev & ADC_REV_SCHEME_MSK) >> ADC_REV_SCHEME_SHIFT,
853 	    (rev & ADC_REV_FUNC_MSK) >> ADC_REV_FUNC_SHIFT,
854 	    (rev & ADC_REV_RTL_MSK) >> ADC_REV_RTL_SHIFT,
855 	    (rev & ADC_REV_MAJOR_MSK) >> ADC_REV_MAJOR_SHIFT,
856 	    rev & ADC_REV_MINOR_MSK,
857 	    (rev & ADC_REV_CUSTOM_MSK) >> ADC_REV_CUSTOM_SHIFT);
858 
859 	reg = ADC_READ4(sc, ADC_CTRL);
860 	ADC_WRITE4(sc, ADC_CTRL, reg | ADC_CTRL_STEP_WP | ADC_CTRL_STEP_ID);
861 
862 	/*
863 	 * Set the ADC prescaler to 2400 if touchscreen is not enabled
864 	 * and to 24 if it is.  This sets the ADC clock to ~10Khz and
865 	 * ~1Mhz respectively (CLK_M_OSC / prescaler).
866 	 */
867 	if (sc->sc_tsc_wires)
868 		ADC_WRITE4(sc, ADC_CLKDIV, 24 - 1);
869 	else
870 		ADC_WRITE4(sc, ADC_CLKDIV, 2400 - 1);
871 
872 	TI_ADC_LOCK_INIT(sc);
873 
874 	ti_adc_idlestep_init(sc);
875 	ti_adc_inputs_init(sc);
876 	ti_adc_sysctl_init(sc);
877 	ti_adc_tsc_init(sc);
878 
879 	TI_ADC_LOCK(sc);
880 	ti_adc_setup(sc);
881 	TI_ADC_UNLOCK(sc);
882 
883 #ifdef EVDEV_SUPPORT
884 	if (sc->sc_tsc_wires > 0) {
885 		sc->sc_evdev = evdev_alloc();
886 		evdev_set_name(sc->sc_evdev, device_get_desc(dev));
887 		evdev_set_phys(sc->sc_evdev, device_get_nameunit(dev));
888 		evdev_set_id(sc->sc_evdev, BUS_VIRTUAL, 0, 0, 0);
889 		evdev_support_prop(sc->sc_evdev, INPUT_PROP_DIRECT);
890 		evdev_support_event(sc->sc_evdev, EV_SYN);
891 		evdev_support_event(sc->sc_evdev, EV_ABS);
892 		evdev_support_event(sc->sc_evdev, EV_KEY);
893 
894 		evdev_support_abs(sc->sc_evdev, ABS_X, 0, 0,
895 		    ADC_MAX_VALUE, 0, 0, 0);
896 		evdev_support_abs(sc->sc_evdev, ABS_Y, 0, 0,
897 		    ADC_MAX_VALUE, 0, 0, 0);
898 
899 		evdev_support_key(sc->sc_evdev, BTN_TOUCH);
900 
901 		err = evdev_register(sc->sc_evdev);
902 		if (err) {
903 			device_printf(dev,
904 			    "failed to register evdev: error=%d\n", err);
905 			ti_adc_detach(dev);
906 			return (err);
907 		}
908 
909 		sc->sc_pen_down = 0;
910 		sc->sc_x = -1;
911 		sc->sc_y = -1;
912 	}
913 #endif /* EVDEV */
914 
915 	return (0);
916 }
917 
918 static int
919 ti_adc_detach(device_t dev)
920 {
921 	struct ti_adc_softc *sc;
922 
923 	sc = device_get_softc(dev);
924 
925 	/* Turn off the ADC. */
926 	TI_ADC_LOCK(sc);
927 	ti_adc_reset(sc);
928 	ti_adc_setup(sc);
929 
930 #ifdef EVDEV_SUPPORT
931 	evdev_free(sc->sc_evdev);
932 #endif
933 
934 	TI_ADC_UNLOCK(sc);
935 
936 	TI_ADC_LOCK_DESTROY(sc);
937 
938 	if (sc->sc_intrhand)
939 		bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intrhand);
940 	if (sc->sc_irq_res)
941 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
942 	if (sc->sc_mem_res)
943 		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
944 
945 	return (bus_generic_detach(dev));
946 }
947 
948 static device_method_t ti_adc_methods[] = {
949 	DEVMETHOD(device_probe,		ti_adc_probe),
950 	DEVMETHOD(device_attach,	ti_adc_attach),
951 	DEVMETHOD(device_detach,	ti_adc_detach),
952 
953 	DEVMETHOD_END
954 };
955 
956 static driver_t ti_adc_driver = {
957 	"ti_adc",
958 	ti_adc_methods,
959 	sizeof(struct ti_adc_softc),
960 };
961 
962 static devclass_t ti_adc_devclass;
963 
964 DRIVER_MODULE(ti_adc, simplebus, ti_adc_driver, ti_adc_devclass, 0, 0);
965 MODULE_VERSION(ti_adc, 1);
966 MODULE_DEPEND(ti_adc, simplebus, 1, 1, 1);
967 #ifdef EVDEV_SUPPORT
968 MODULE_DEPEND(ti_adc, evdev, 1, 1, 1);
969 #endif
970